An arrangement in which, when a connector is joined to a floor fuel tube made of metal and a fuel tube made of resin is joined to this connector, a clamp is installed between the floor fuel tube and the connector so that the two are not separated is known from Patent Publication 1 below.
The clamp is a box-shaped member having one open face and is equipped with a U-shaped cutout in each of two mutually opposing faces; one of the cutouts is fitted onto the outer periphery of the floor fuel tube so as to retain it in the axial direction, and the other cutout is fitted onto the outer periphery of the connector so as to retain it in the axial direction, thereby restraining the floor fuel tube and the connector so that they are not separated.    Patent Publication 1: Japanese Patent Application Laid-open No. 6-323483